Electric terminal strips have been known for decades and are used in their millions in the wiring of electrical systems and equipment. The terminal strips are usually latched onto mounting rails which for their part are frequently arranged in a plurality in a switch cabinet. Screw terminals or spring-cage terminal blocks are mainly used as conductor connection elements in terminal strips. However, insulation displacement terminals or leg spring terminal blocks can also be used in addition.
The basic type of terminal strip is the connecting terminal with at least two conductor connection elements which are joined to each other electrically by way of an electrically conductive connection rail, the busbar. In addition to this basic type, which is also often referred to as a feed-through terminal block, there are many different types of terminal strips which are specifically adapted to the respective application. Protective conductor terminals, disconnect terminals and test terminals are mentioned as examples.
Particularly in the case of terminal strips, which are used in current transformer measuring circuits in power generation, transmission and distribution, various switching, disconnecting and testing tasks frequently have to be implemented. For this there are various accessories, such as test plug sockets, fixed bridges or switching jumpers, which can be mounted in terminal strips and electrically connected to the busbar. Using fixed bridges, it is possible in this case to implement distribution of potential between adjacent terminal strips in a simple manner. Switching jumpers are used to join two or more adjacent terminal strips electrically to one another as required so that there is an option to short-circuit a connected current transformer.